bring on vs touch off

bring on

verb
  • To cause. 

  • To pose a challenge or threat; to attack; to compete aggressively. 

  • To make something appear, as on a stage or a place of competition. 

touch off

verb
  • To start; to cause, especially used for unstable situations that may magnify if disturbed. 

How often have the words bring on and touch off occurred in a corpus of books? (source: Google Ngram Viewer )